Hydrometer



1954 F. R. WILSON HYDROMETER Filed March 20, 1948 7 Mm mU n METHANOL No TEST J TEST Patented Feb. 9, 1954 UNITED STATES PATENT OFFICE The invention relates generally to hydrometers and more particularly to a hydrometer adapted for testing the coolant in the cooling system of an internal combustion engine to determine what freezing temperature the coolant can withstand.

One object of the invention is to provide a testing device of new and improved construction, particularly adapted to indicate quickly and conveniently, yet accurately, the freezing temperature, already corrected to take into account the temperature of the fluid being tested, which the fluid being tested will withstand.

Another object of the invention is to provide a testing device constructed in a new and improved manner to give an accurate reading, corrected as to the temperature of the fluid being tested, when the make of antifreeze compound in the fluid is known and to give a safe reading when the make of antifreeze compound is not known.

Still a further object is to provide a device adapted to test the freezing temperature that a solution will withstand having means including a float carrying a pair of separate scales indicating the specific gravity of the solution, a thermometer for indicating the temperature of the solution, and means for translating the specific gravity and the temperature indications into a measure of the freezing temperature that the solution will withstand including a pair of plates extending generally parallel with the temperature indicating means, each having a pair of graduated temperature value columns and an element mounted on each of said plates for slidinglongitudinally thereof, the one bearing one of the scales and the other bearing the other of the scales on the float and having apertures therein indicating the freezing temperature which the solution being tested will withstand when the character indicating the specific gravity of the solution is placed opposite the temperature indication.

Other objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings, in which: 7

Fig. 1 is an elevational view of an embodiment of my invention.

Fig. 2 is a transverse sectional view taken approximately along the line 22 of Fig. 1.

While the invention is susceptible of various modifications and alternative constructions, it'is shown in the drawings and will hereinafter be described in three embodiments. It is not intended, however, that the invention is to be limited thereby to the specific disclosure made.

On the contrary it is intended to cover all additional modifications and alternative constructions falling within the spirit and scope of the invention as defined in the appended claims.

As is well known to those versed in the art, the freezing temperature which a solution com posed of water and some freezing-temperature' lowering compound will withstand, commonly the coolant employed in the radiator of an automoble, is determined by ascertaining the specific gravity of the solution and then correcting it to taken into account the effect of the temperature of the solution at the time the test was made. It is also known that there are antifreeze compounds, that is, freezing-temperaturerlowering compounds which when added, to water result in a solution having a specific gravity greater than that of water, and others which result in a solution having a specific gravity less than water. Moreover, each of the compounds now onthe market produces a different freezing temperature which the solution may withstand, even though the specific gravity reading ofthe solution may be the same. It has thus in the past been necessary for a filling station or garage attendant, in testing the solution in a radiator, to measure or receive an indication of the specific gravity of the solution and the temperature of the solution, then go to a chart posted on a bulletin board and laboriously determine from the chart the indicated freezing temperature which the solution will withstand provided he knew definitely and specifically the specific antifreeze compound which was in the radiator. If he did not know what compound was in the radiator, it was only through laborious use of a plurality of charts that he could indicate a, freezing temperature that the solution would withstand with safety and, if there was a mix-' ture of compounds, the attendant was more or less completely at a loss to indicate what freezing temperature the solution could withstand.

It is to facilitate this determination of the freezing temperature which a solution will withstand that I have perfected the testing devices herein disclosed and claimed; Generally, these devices comprise means for obtaining an indication of the specific gravity of the solution being tested, means for obtaining an indication of the temperature of the solution, and means mounted on and carried by the device operable quickly and conveniently yet accurately to translate these indications of the specific gravity and the tem-' perature into a measure or indication of the freezing temperature which the solution will withstand. The translating means is, however,

so correlated with the temperature indicating means that the top of the column of temperature responsive fluid is employed directly in the determination of the freezing temperature of the solution, as distinguished from the necessity of reading from the temperature indicating means some numerical value or even some arbitrary relative temperature indicating character which must then be coordinated with some equivalent character on a .difierent scale; Moreover, the translating means is so devised that, if it is known that the solution contains any one of four common antifreeze compounds, a definite indication of the freezing temperature of the solution is given and, if the compound is unknown, or if there is a mixture of compounds of the same class, that is, those having aspecific gravity heavier than water, or those having a specific gravity lighter than water, a reading as to a safe freezing temperature is given.

As shown in Figs. 1 and ,2 t e t t n device comprises means it" for obtaining an indica tion of the specific gravity of the solution, means H for obtaining indication of the tempera ture of the solution, and means 13" tor translating the specific gravity and the temperature indicationsinto .a measure of the freezing tem,-: perature which the solution, will withstand. The specific gravity indicating means L and the temperature indicating means ll are more or: less of conventional construction, with the former comprising .a tube, .a cylinder, or a barrel M of glass or some other suitable transparent maeterial. At one end, the lower end as viewed in. Fig. 1, the tube I4? is seated in a base or :tip, l5 usually of rubber or an equivalent mate--. rial. This base has formed integrally therewith. a longfiexiblerubber tube 16" adapted to be inserted into the radiator or other container in which the solution to be tested is contained. At I its opposite end, the tubei 4 carries a bulb lJ-" utilized in well known-manner to draw the solu-; t-ion to be tested into the barrel-1 4 or to. dis charge the same therefrom. Within the barrel M isa float l8 composed of the usual enlarged or bulb'portion s c"- and stem 20 thefloatbeing being received-in the barrel M with its bulb portion is" toward the inlet end of the barrel. Herein the ster'nof the float carries twcscales 21 and '22 of generally-similar nature save that they are composed of different characters. The characters composing the scales herein are 'let-'' ters, though, obviously, any other characterswould serve the purpose-andthe-scales arearranged tandem relation along the stemand divided by a space bearing the-character W'wh-ich, oi course, indicates a solution having the specific gravity of water. The scales are graduated with the characters falling closer together as one progresses away from the character W;

' The temperature indicating means l""' is a simple thermometer having a bulb 23 and a capillary tube 214". The bulb.2.3j"' .is disposedv so as to be exposed to the solution drawninto the, barrel [4 to be tested, while. the tube 2 4"1ex.- tenfiS pwardly from the base 15' within but immediately adjacent tofthe inner surface of the barrel i l", so as tobe clearly visible through the,- barrel. Contained in the thermometer is av suitable temperature responsive fluid. 25". The thermometer is supported in position by having a part of the tube 24" embedded in the base 15 and is further supported in position by means of, a. rub ber sleeve 28 which lines the lower portion-oi,

28" almost completely surrounds the tube 24" of the temperature indicating means and thus protects the tube against breakage by striking of the float thereagainst, and also prevents solution from surrounding the tube 24" thereby producing enhanced readability of the temperature indicating means by eliminating the difiraction which would otherwise be produced by the solution.

When solution to be. tested is drawn into the barrel Hi", the float, of course, seeks a level in the solution determined by the specific gravity thereof. If the solution is simply water, the float will to the point where the level of the solution will be opposite the space bearing the character W. If the solution contains an anti-freeze compound which has a specific gravity heavier than water the iioat will, of course, rise in the solution and give a reading on the scale 22" depending upon the quantity of antifreeze compound of that .character'which has been added. Gonversely, if the antifreeze compound has a specific gravity less than water, the float will sink deeper into the solution and give a reading on the scale 21. Thus the position of the float in and of itselfindi cates to the attendant whether-he is dealing with a solution containing a compound having a specific gravity less than water or a compound having a specific gravity greater than water, as does also the scale from which the reading is taken;

The translating means l3 herein comprises three main parts, two of which are movable, but only one of which need be moved to obtain an indication as to the freezing temperature which asolution being tested will withstand. The sta tionary part or the translatingmeans l3 takes. the form of a pair of elongated tablets it and H extending longitudinally of the barrel HI"- and rigidly secured in position by a pair of clamps "l3. surrounding the barrel it" as best seen in fig; 2 Formed in each of the tablets wand-H is a harrow elongated and longitudinally extending s lot r4. Alongside of the slot 1-4 are two actions of figures representing Fahrenheit temperatures. lhese figuresrange from a temperature of 3 2" to 40 or below zero and itis to be noted that the numbers composing the columns on the tablet it run in the opposite direction from' the hum} bers composing the columns on the tablet Hf. In the commercial construction of the device,

the above zero numbers and the belowzeiionumrhers are presented contrasting colors with the. below zero figures ally shown in. red. but rioan t mpt has here bee made to indicate such differ ence in coloring the below zerofigures being read:

' iiy recog'nized from-the location oi the. metals.

352. As'in the oth r forms, theleit hand one-of the columns cneach of the ans-s 1t andnLrepre-i sents the freezing temperatures which a solution. containing varying amounts of a. known freeze compound willwithStand. The righthand.

column of figures, on the, other handrissolcalibrated as to give a safe reading when theii'ecze compound in thesoluticn i s unl no,wnL

' The movable parts of the translatingineans :53." comprise two. rectangular piates'fisf and 26; The plate is, as by a pair of riuets'tl-eigtenda i g through the, slot 14, mounted for sliding movement longitudinally of' the tablet 1'! While the plate .18 is similarlymounted on 1th ablet Ll. Each of, the platesis formed with. a a bi; apertures 18, and 159 so-located thattheyq'q with the columns offigures on the; tablets-1, 0. and 11. Along itsginner side edge, the: plate; H15 qer es a scale: which; correspondent the; scale.

inner edges of the plates are located as'closely adjacent the tube '24" of the thermometer as the barrel [4" permits so that the plates 15 and i6 may readily be adjusted with respect to the height of the column, of temperature responsive fluid25". To facilitate movement of theplates Hand 16', each is provided witha finger grip 80-.' It will be appreciated,- of course, that "the various columns offigures, scales, and the colof temperature responsive fluid are so calibrated and positioned that-when the plate 15 or theplate 16 is adjusted to have the letter'on the scale thereon, corresponding to the specific gravity reading obtained from the float l8, opposite the top of the column of temperature responsive fluid, the number visible in the apertures 18 or 19 will be an indication of the freezing temperature which the solution being tested will Withstand corrected to take into account the temperature of the solution at the time of the test.

While it is believed that the operation of the solution is to be tested which is known to be composed of water and a known antifreeze compound sold in the trade under the name Prestone. Let it also be assumed that the temperature of the solution is as indicated by the column of temperature responsive fluid 25" in Fig. 1, and that the specific gravity of the solution is such that the float rides in the solution to give. a reading of N; Thus by the simple operation of drawing a quantity of the solution into the barrel 14" the above recited information will be given to the attendant. All the attendant need do to obtain an indication of the freezing temperature which that solution will Withstand is to adjust the plate 15 so that the character N is opposite the top of the column of temperature responsive fluid 25": He then looks to the aperture 18 in the plate 15 and framed in that aperture will be a number or numbers which Will in? dicate the lowest temperature which the solution will withstand without freezing. 'Because the figures are hidden by the present position of the slide 15, an exactdetermination is not possible from the drawings, but it would appear that the reading would besomewhere in the neighborhood of 12 above zero. If it be assumed that the antifreeze compound in the solution is unknown, or if there is a mixture of compounds of the same general class, a safe reading is quickly and readily obtained by following the same proabove pointed out, the right hand column on each of the tablets 10 and H is so scaled that it gives for any specific gravity of the solution the highest temperature taking into account any and all known antifreeze compounds.

If the solution contains a lighter than water antifreeze compound, the float reading, of course, will be on the scale 2|"; The procedure, however, is the same and still requires only adjustment of the plate '16 to bring the character on the plate, corresponding to the reading on the float, opposite the top of the column of temperature responsive fluid 25". If it be assumed that the solution gives a float reading of D which is well upon the scale 2 l indicating a large content of antifreeze compound, and if the compound'is known' to be methanol, the attendant simply adjusts the plate 16 to the position shown, namely, with the letter D opposite the top of the column 25" and then looks to the aperture 18 and finds that the solution will withstand a temperature of 45 below zero. If the compound in the solution is unknown, or if it is known to consi'st of a variety of compounds, the attendant can immediately learn of a safe figure by noting the number in the aperture 19 which, as shown, is only 25 below zero.

I claim as my invention:

1.' A device for determining the temperature at which a solution will freeze comprising meansfor obtaining an indication of the specific gravity of the solution including a tube into which the solution to be tested is drawn and a float within said tube having'thereon separate scales respectively indicating the specific gravity of h eavier than water solutions and lighter than water solutions, means for obtaining an indication of the temperature of the solution includingha column of temperature responsive fluid extending longitudinally of said tube and a bulb exposed to the solution drawn into the tube, and means for translating the specific gravity indication and the temperature indication into a measure of the freezing temperature which the solution will withstand comprising a first part fixed on said tube, a second part composed of a pair of plates each mounted for movement longitudinally of said tube and longitudinally relative to said first part and to said column of tempera, ture responsive fluid, the scale on one of said plates corresponding to specific gravity indica-:

tions lighter than water and the scale on the other of said plates corresponding to specific gravity indications heavier than water, a plural-' ity of columns of figures representing temperatures carried by said first part, said columns extending generally longitudinally of said tube, said scales 'andsaid columns being calibrated to give an indication corrected as to the temperature which the solution will withstand by adjusting the appropriate one ofsaid plates to have the character on its scale corresponding to the specific gravity indication disposed opposite the top of the column of temperature responsive fluid. 2. A device for determining the temperature at which a solution will freeze comprising means for obtaining an indication of the specific gravity of the solutionincluding a tube into which the solution'to be tested is drawn and a float within said tube, a plurality of scales extending longitudinally in tandem relationship on the stem of said float, means for obtaining an indication of the temperature of the solution including a column of temperature responsive fluid extending longitudinally of said tube and a bulb exposed to the solution drawn into the tube, and means for translating the specific gravity indication and the temperature indication into a measure of the freezing temperature which the solution will withstand comprising a first part fixed on said tube and through which said column of temperature responsive fluid is visible, a second part composed of a pair of plates each mounted for movement longitudinally of said tube and longitudinally relative to said first part and to said column of temperature responsive fluid, a scale on the edge of each of said plates adjacent the column of temperature responsive fluid corresponding to one of the scales on said float, the scales on said plates and the scales on said float having the characters composing the same running in the samesdi'mction, apluralit rof columns; ofiffi'suresr representing temperatures carried by Said first. part; said columns: extending. enerally lQngi.-- tudinallyof; said tube: anclgroupedto he assooi ateiwith; one or the other of; said plates. the figuressof. one of the groupsotcolumns running: downwardly from; freezing to. lowv temperature valuea-and the figures oftheothergroun of: calf-.- umns: running, downwardly frQm. .1OWft8mDBI-K=- tures. tosfreezing' temperature; said scales aandotaicl; columns being calibrated to givegan: indication corrected s to th mperaturcawhichithe solutlon will withstand by adjusting thezappl'flnriate one; of: said: plates to have the character: on its scale. corresnond to the specific gravity indicae tionrdisposecl opposite the.- to of the. column of. temperature responsive fluid.

3:1A device for determining. the. freezing tem perature which. a solution, will. withstandi coma pr-isingatube into which the solutionto betesteda isdrawn; a. float; within said tube, apair of scales carriedaby the. stemoi: said; float, the one indicat ing specific, gravities lighter thanwater, the other specific ravities heavier than, water,- meanstior. obtaining an. indication of the temperatureof; the-solution including a column of. temperature. responsive fluid extending, longitudinally of. said tube and; a bulb ex osed to the solution: drawn into: the. tube, and means for translatin thev pecific gravity indication. and the temperature; indioationinto a measure of the freezing term p rature which; the solutionwill withstand. com..- prisingapairof elongated tablets fixedly mount.- ed. on saidtube-extending longituclmall thereof, a nlatemounted on each of said tablets iorslidmg; movement longitudinally ther f, a pair of. columns of temperature intlicating fi ures on each of said-tablets. e ehof saidplates having .a p ir. oi ap rtures formed therein hr u h which he. fi ures 0i said columns ar visible a the: plates are adjust d-longitudinally oi: said tablets an aseale oueaoh of said plate, adjacent said column. of emperature respon ive. fluid. the-scale on on fv said: plat s rrespondin t the: upperscale: on said. float and the scale onrthe. o her oi said plates. corresponding to thelower scale said flo t..said scales and columns bein so. oalia btated that. when the appropriate.- platelet-all J'usted. to: have; the character of its. scale corresponding. to the: specific. gravity of. the solution disposed, opposite the. top of. the column of tam: nerature; responsivexfluid an mdicationas tuthe specific: gravity ofz heavier: than; water s lut ns:

and; lighterthanwater; solutions. means or ob talnms: an indication of the tempeltature of. the: solution including: a. column. of; temp rature. to. sponsivo. fluid extendi longitudinal y of; said.

15 tube and; a; bulb. exposed: to the soluti n. drawn.

into the tube. and; me ns: tor.- trahslating; the: spe ific. gtavity intimation. and th tempe ature ndication into a m asu e oi the .freez h stems perature which thesolution. will w thstand: eom p sin arflrst. part. fixe on sa dtube, a-see hsl hart composed of a. h irof mates. ea h: mou ted. for nd pendent mo ement lon i ud nallyofi said: tube and longitudinally relative to said first pant and to sa cl eo umnof. t mpe ature re ponsi fluid; aaseale ori oneoi sa hlates corr sp nd n t -theispecifwse'rav-ity .ihdicationsfor li hter than. w ter s lutions onead float. nd; ais ale; on. the. th r of said plates oor eshonclin to the. see-- cifie. gra ty indications of hea ier th n wate soluti ns. on said float, a. hlu ality o lirl l1&- tui'e scales. carried by sale first pai;t ..sa tome: perature sea-l e extendin g nerallylen itudin 1.-.- tl f s id tube, ale soeoif e r vity in imat n: scalesand said t mpetat re Beatles; b ing. all brat d o ,eiivean; indi ation eonreetee as; tome temperature which. the solution will w't ta-ocl: by adjusting the. appropriate oisald: p ates; to have the oharaeter ehaits seale e rto p r d h to the speeifit g avi y imitation re d i emsa h floatv d sposed pu sit the top-of; t e. eolumu o1: temperature responsive fluid.- 

